Detergent composition

ABSTRACT

An aqueous detergent composition comprises, by weight, (a) 18-40% R(OC2H4)xSO4M, wherein x is 0-4; (b) a trialkyl amine oxide, the weight ratio (a); (b) being 1-7: 1; (c) 1.8-10%, but at least 20% by weight of (b), alkyl glyceryl ether sulphonate; and (d) at least 5%, but preferably not more than 40% of methanol, ethanol, n- or iso-propanol, or mixtures thereof.  (a), (b) and (c) each contain a C10-14-straight chain alkyl group of which at least 50% contains 12 carbon atoms; (b) contains two alkyl groups which each have 1 or 2 carbon atoms, and the cation in (a) and (c) is mono-, di- or tri-ethanolamine, ammonium, sodium, or potassium. (a) is preferably the ammonium salt of the sulphated condensate of 3 mols. ethylene oxide with 1 mol. middle cut coconut alcohol, and the weight ratio of (b) to (c) is usually at least 1:1.  Up to 5% of sodium, potassium or ammonium toluene or xylene sulphonates, or mixtures thereof may be present. Inorganic salts in amounts up to 12%, e.g. sodium nitrate, potassium chloride, or ammonium phosphate, opacifiers such as ethylene glycol distearate or polystyrene in amounts up to 3%, citric acid, perfume, viscosity control agents, colour and perfume may also be incorporated. Specifications 802,325 and 992,754 are referred to.

United States PatentOfiFice l 3,179,599 Patented Apr. 21), 19653,179,599 DETERGENT COMPOSETION Stanley Lee Eaton and Edmund FrederickGebhardt, Cineinnnati, Ohio, assignors to The Procter dz Gamble(Iompany, Qincinnati, Ohio, a corporation of Ohio No Drawing. Filed July3, 1961, Ser. No. 121,341 3 Claims. (til. 252-153) by the amount of sudspresent and will very likely be misled if the suds do not persist for areasonable period of time.

There are many dificulties associated with formulating a high-sudsing,light-duty liquid detergent. An ideal liquid detergent composition isclear and colorless, permitting the formulation of a Wide variety ofopaque,

clear, colorless and colored detergents. However, the

most common suds builders are amides, which tend to color the productyellow. An ideal liquid detergent is also one where the majoringredients are highly compatible so that only a minimum amount ofsolubilizing agent is needed to keep the detergent in a single phase,yet many detergent surface active agents and suds builders are notunlimitedly soluble in water, especially in combination with each other.Furthermore, the ideal liquid detergent would be suitable for use withall kinds of soil and wash water, including acid soil and wash Water.

Accordingly, it is an object of this invention to provide ahigh-sudsing, light-duty liquid detergent which maintains as much aspossible its sudsing performance under acid conditions.

It is a still further object of this invention to provide a highsudsing,light-duty liquid detergent which does not contain an amide type sudsbuilder.

It is another object of this invention to provide a singlephase,high-sudsing, light-duty liquid detergent requiring only a relativelysmall amount of a solubilizing agent.

The unbuilt, high-sudsing, light-duty liquid detergent compositions ofthis invention consist essentially of: (1) from about 20% to about 40%by weight of the composition of a sulfate detergent surfactant havingthe following formula .having 12 carbon atoms and two short chain alkylgroups having from one to about two carbon atoms in an amount such thatthe weight ratio of sulfate detergent surfactant to amine oxide is fromabout 1/1 to about 7/1; (3) from about 2% to about 10% by Weight of thecomposition of an alkyl glyceryl ether sulfonate having a straight chainalkyl group having from about 10 to about 14 carbon atoms with at least50% of said alkyl groups having 12 carbon atoms, the cation of saidsulfonate being selected from the group consisting of monoethanolamine,diethanolamine, triethanolamine, ammonium, sodium and potassium cationsand mixtures thereof, the amount of said sulfonate being at least 20% ofthe amount of said amine oxide; (4) at least about 5% by Weight of thecomposition of a solubilizing agent selected from the group consistingof methyl, ethyl, n-propy1, and isopropyl alcohols; and (5) the balancewater. Other minor ingredients including from zero to about 5% by Weightof the composition of a viscosity control agent such as eitherpotassium, sodium, or ammonium toluene sulfonate or potassium, sodium orammonium xylene sulfonate; perfume; opacifiers; and coloring can beadded.

It has been discovered that the amine oxides of this invention build(enhance) the sudsing ability of the sulfates of this invention to ahigh degree, but do not build the sudsing ability of the sulfonates, orsulfate surfactants containing aromatic configurations to the extentdesired in light duty detergents having a pH in the range of 6.5 to 9.0.As used herein, sudsing ability refers to both the initial quantity ofsuds and the persistence of the suds throughout the Washing operation.The persistence (stability) of the suds of the composition of thisinvention is extremely good under alkaline, neutral, and acidicconditions. It has also been discovered (as set forth in the copendingapplication of Norman R.

Smith, Serial No. 121,340, filed concurrently herewith) that unless theweight ratio of sulfate surfactant to amine oxide is at least 3/ 1, thesudsing ability of the composition is practically eliminated under acidconditions such as might exist where the pH of the wash Water Was lessthan about 6.5. This may occur Where the Water itself is acid or wherethe. soil on the objects to be washed isacid. On the other hand,compositions with Weight ratios of sulfate surfactant to amine oxidegreater than 7/1 lose sudsing ability both in acid and neutral washWater.

This sudsing sensitivity of combinations of sulfate surfactant and amineoxide to acid conditions can be controlled very satisfactorily by theinclusion in the composition of from about 2% to about 10% by weight ofthe composition of a monoethanolamine, diethanolarnine, triethanolamine,sodium, potassium, or ammonium alkyl glyceryl ether sulfonate ashereinbefore described. The addition of this sulfonate permits the usageof sulfate surfactant to amine oxide ratios of from about 1/1 about7/ 1. The sulfonate not only permits the use of sulfate surfactant toamine oxide ratios of less than 3/1 under acid conditions, it alsoincreases sudsing performance for almost all ratios of sulfatesurfactant to amine oxide within the broad range hereinbefore mentioned.This is a very surprising result since a composition containing only thealkyl glyceryl ether sulfonate and amine oxide in an unbuilt product,does not perform as satisfactorily as the sulfate alone as far assudsing ability is concerned under either acidic or neutral conditions.Only in ternary mixtures as hereinbefore described, do the alkylglyceryl ether sulfonates of this invention have a synergistic effectupon sudsing ability.

As a general rule, weight ratios of sulfate surfactant to amine oxide ofless than l/l are preferably not used from the standpoint of mildness,and there is a loss in sudsing performance with ratios above 7/1, evenwith the inclusion of the sulfonates of this invention.

The loss of sudsing ability under acid conditions isordinarilymanifested only in unbuilt detergents. Whereas the pH of aliquid detergent built with substantial quantities of ordinary phosphatebuilders and/ or silicate salts and/ or other alkaline builders isaround 10 or above, the pH of the unbuilt liquid detergents of thisinvention and of unbuilt liquid detergents in general is about 6.5 to9.0 In addition to this initial alkalinity in built liquids, the builderprovides a reservoir of alkalinity so that there taining these groups.

must be a considerable amount of acidic material present in the washwater before the pH will be lowered to a 'level Where substantial lossof sudsing ability is encountered with detergent sulfate to amine oxideweight ratios outside the scope of this invention. However, when only arelatively small amount of acidic material is present in the wash waterand/ or soil, the addition of unbuilt liquid detergents to the Washwater will, in general, leave the wash water with an acid pH.

As hereinbefore mentioned, the sulfonate should be present in an amountequal to at least about by Weight of the amount of amine oxide present.This amount is required to give satisfactory sudsing performance underacid conditions. From an economic standpoint, the ratio of amine oxideto alkyl glyceryl ether sulfonate should not be less than about 1/1since an increase in the amount of sulfonate above the amountrepresented by this ratio does not give appreciably better performance.

The concentration range of sulfate detergent surfactant is set at thelower limit of 20% by sudsing considerations and at the upper limit ofby viscosity considerations.

At lower levels the quantity of suds is drastically reduced and at hiher levels the product is no longer pourable.

The sulfate detergent surfactant itself has certain requirements as tothe length of the alkyl chain. Chain lengths of less than ten carbonatoms give reduced detergency and sudsing and chain lengths greater than14 reduce the quantity of suds which are produced. Somewhat the sameconsiderations apply also to the chain length of the long alkyl group inthe amine oxide surfactant.

Shorter chain lengths lead to decreased detergency, sudsing, and sudsbuilding as do longer chain lengths. The

the amine oxide for the same reasons of sudsing and detergency mentionedabove since this is the optimum chain length.

' The length of the short alkyl groups in the amine oxide is set byconsiderations of solubility. Groups which are longer than about twocarbon atoms inhibit the solubility of the amine oxide in the water.

A sulfate detergent surfactant containing no ethylene oxide groups is aneffective detergent and sudser, but is not quite as mild as a sulfatedetergent surfactant con- However, more than about four ethylene oxidegroups in the molecule will substantially reduce sudsing capacity. Thepreferred sulfate detergent surfactant contains an average of threeethylene oxide groups per molecule. In general, all of the compositionsof this invention are mild when applied to human skin.

Preferred alkyl glyceryl ether sulfonates are described in CanadianPatent 582,404.

The finished composition requires'the addition of a solubilizing agentto prevent phase separation. Although much less solubilizer is neededwhen an amide is not present, still at least about 5% of thesolubilizing agent is necessary. Too much solubilizing agent would betoo costly and tends to adversely affect viscosity, so that only enoughsolubilizing'agent should be included in the composition to keep thecomposition in a pourable single phase under conditions of use, but notmore than about 40% by weight of the composition.

As hereinbefore mentioned, various minor ingredients including perfume,viscosity control agents, opacifiers, and

The toluene sulfonates and xylene suhonates hereinbefore described aredesirable minor additives in amounts up to 5%. They increase theviscosity of the compositions. Other desirable additives includeopacifiers such as ethylene glycol distearate or polystyrene in amountsup to about 3% by weight of the compositions.

The compositions of this invention do not contain conventional sudsbuilders such as amides. The superior sudsing ability of thesecompositions makes it unnecessary to have such suds builders present,which results in cost advantages and simplified formulation. Also, sincethe most common suds builders are amides, which have odors and whichcolor the product, the compositions of this invention have better odorand better color than many prior high sudsing compositions. Amides alsotend to cause phase instability which can only be'corrected by addingmuch more solubilizing agent than is ordinarily required in compositionsof this invention.

The following examples will demonstrate the unique advantages of thecompositions of this invention as op tion.

Example I The following compositions contained varying amounts of theammonium salt of the sulfated condensation product of one mole ofmiddle-cut coconut alcohol containmg 1t 12, 14; and 9%C16 alkyl groupswith three moles of ethylene oxide (A), a tertiary amine oxide having along alkyl chain derived from the same middle-out coconut alcohol andtwo methyl groups (B), and sodium alkyl glyceryl ether sulfonate whereinthe alkyl group is derived from the same middle-cut coconut alcohol (C).The compositions also contained 10% ethyl alcohol and the balance water.All percentages contained herein are by weight of the composition.

In order to evaluate the sudsing ability of these compositions, 7.25 cc.of each of the compositions was added to a dishpan containing one gallonof water with a hardness of 7 grains, a temperature of F., and pHs of 7and 5 for two separate trials. Suds were generated by mechanicalagitation (small propeller) and the suds level measured. A fixedquantity (about 5 grams) of standardized fatty soil (2. triglycerideshortening) was placed on a dinner plate which was then washed in thetest solution. The plate was re-soiled and washed, repeating thisprocedure a total of five times. Five additional sets of five soiledplates were washed in the solution in like manner, measuring the foamheight after each set. The foam height after washing each set wasexpressed in terms -of percent of original suds height and an average ofthe Composition 1 2 3 4 5 6 7 8 9 10 Percent A 25 25 25 25 25 20 20 2020 20 Percent B 5 5 5 5 5 5 5 5 5 5 Percent C 0 1 2 3 4 0 1 2 3 4Percent Ethyl alcohoL 10 10 10 10 10 10 1O 10 10 10 Percent Water bal.bal. bal. bal. bal. bal. bal. bal. bal. bal. Ratio A/B 5 5 5 5 5 4 4 4 44 Performance at pH 7 49 5O 53 53 54 44 44 44 45 48 Performance at pH5..." 35 43 5O 50 51 29 31 36 38 36 Composition 11 12 13 14 15 16 17 1819 20 PercentA 15 15 15 15 15 20 20 20 25 25 Percent B- 15 15 15 15 151O 10 10 10 10 Percent O 0 4 6 8 10 0 4 5 O 2 Percent Ethyl alcohol 1010 10 10 10 10 10 10 10 10 Percent Water bal. bal. bal. bal. bal. bal.bal. bal. bal. bal. Performance at pH 47 45 38 4O 45 39 41 43 48 48Performance at pH 5 35 38 41 43 37 32 32 1 Sudsing was too low tomeasure by this test method.

As can be seen from the preceding data, compositions with weight ratiosof sulfate detergent surfactant to amine oxide of more than 3/1(Compositions 1-10) all have acceptable sudsing performance. However,compositions without sodium alkyl glyceryl ether sulfonate (Compositions1 and 6) did not perform as well relative to sudsing as thosecompositions containing sulfonate (Compositions 2-5 and 7-10).

As can also be seen from the preceding data, compositions with a weightratio of sulfate detergent surfactant to amine oxide of less than 3/1(Compositions 11-20) did not perform well at all under acid conditionswhen there was no sulfonate present (Compositions 11, 16 and 19), butperformed exceptionally when there was even a small amount of sulfonatepresent (Compositions 12- 14, 17, 18, and 20).

Therefore, it is readily apparent that the addition of an alkyl glycerylether sufonate of this invention to a combination of the sulfates andamine oxides of this invention gives exceptionally good results.

Example ll A detergent composition was prepared containing 25% by weightof the composition of the sulfate detergent surfactant of Example I, 5%by weight of the composition of the amine oxide of Example I, 2% byweight of the composition of the alkyl glyceryl ether sulfonated ofExample I, 1% by weight of the composition of ammcnium phosphate, 12% byweight of the composition of ethyl alcohol, 0.3% by weight of thecomposition of perfume, 0.2% by weight of the composition of a 1% byweight color solution, 0.1% by weight of the composition of citric acid,and the balance water. This composition was tested under typical homeuse conditions and found to be a very satisfactory high-sudsing,light-duty liquid detergent under alkaline, neutral, and acidicconditions. The ammonium phosphate present in this and subsequentexamples is present only in small amounts for the purpose of adjustingthe pH of the product and is not present. as a builder.

When the sulfate and sulfonate detergent surfactants in the precedingexample are the monoethanolamine, diethanolamine, triethanolamine, orpotassium salts, substantially equivalent results are achieved.

Similarly, when the ethyl alcohol solubilizing agent is replaced bymethyl, isopropyl, or normal propyl alcohols, substantially equivalentresults are achieved.

Also when ammonium and sodium exylene sulfonates and sodium and ammoniumtoluene sulfonates are added to the composition of the above example ofthe composition, substantially equivalent results are achieved.

Example 111 A detergent composition was prepared containing 25% of thesulface detergent surfactant of Example I, 5% of the amine oxide ofExample I, 4% sodium alkyl glyceryl ether sulfonate wherein the alkylgroup is derived from the same middle-cut coconut alcohol as thesulfate, 2% potassium toluene sulfonate 6% ethyl alcohol, 2% potassiumchloride, 1% ethylene glycol distearate, 0.1% critic acid, 0.15%perfume, 0.09% brightener, and the balance water. All percentages hereinare by weight of the composition. The composition was tested under homeuse conditions and found to be an effective highsudsing, light-dutyliquid detergent under alkaline, neutral and acidic conditions.

Example IV A detergent composition was prepared containing 25 of thesodium salt of the sulfated condensation product of one mole ofmiddle-cut coconut alcohol, as hereinbefore described, and three molesof ethylene oxide; 6% lauryl dimethyl amine oxide; 4% sodium alkylglyceryl ether sulfonate wherein the alkyl group is derived frommiddle-cut coconut alcohol as hereinbefore described; 3% sodium alkylglyceryl ether sulfonate wherein the alkyl group was derived fromtallow; 12% sodium nitrate; 8% ethyl alcohol; 2% sodiumtoluenesulfonate; 0.15% perfume; and the balance water and miscellaneousinert in- Example V A detergent composition was prepared containing 21%of the sulfate detergent surfactant of Example I, 4% of the amine oxideof Example I, 2% of the alkyl glyceryl ether sulfonate of Example I, 1%ammonium phosphate, 0.1% citric acid; 0.3% perfume, 12% ethyl alcohol,0.2% of a 1% by weight color solution, and the balance water andmiscellaneous inert ingredients. All percentages herein are by weight ofthe composition. This composition was tested by the test of Example Iand found to have a performance at pH 7 of 44 and a performance at pH 5of 35. This was an exceptionally good sudsing lightduty liquiddetergent.

What is claimed is:

1. An unbuilt, high-sudsing, light-duty liquid detergent compositionhaving a pH of from about 6.5 to 9.0 and having special utility underacid conditions such as might exist where the pH of the wash water isless than about 6.5 and consisting essentially of (1) from about 20% toabout 40% by weight of the composition of a sulfate detergent having thefollowing formula wherein R is a straight chain alkyl group having fromabout 10 to about 14 carbon atoms with at least 50% of said alkyl groupshaving 12 carbon atoms, x is a number from zero to about four, and Me isselected from the group consisting of monoethanolamine, diethanolamine,triethanolamine, ammonium, sodium, and potassium cations; (2) a trialkylamine oxide having one straight chain alkyl group having from about 10'to about 14 carbon atoms, with at least 50% of said alkyl groups having12 carbon atoms, and two short chain alkyl groups having from one toabout two carbon atoms, in an amount suflicient to give a ratio ofsulfate detergent to amine oxide of from about 1/1 to about 7/1; (3)from about 2% to about 10% by weight of the composition of an alkylglyceryl ether sulfonate having a straight chain alkyl group having fromabout 10 to about 14 carbon atoms with at least 50% of the said alkylgroups having 12. carbon atoms, the cation of said sulfonate beingselected from the group consisting of monoethanolamine, diethanolamine,triethanolamine, ammonium, sodium, and potassium cations and mixturesthereof, the amount of said sulfonate being at least 20% of the amountof said amine oxide; (4) at least about 5% but not more than about 40%by weight of the composition of a solubilizing agent selected from thegroup consisting of methyl, ethyl, n-propyl, and isopropyl alcohols, andmixtures thereof; and (5) the balance water.

2. The composition of claim 1 containing from zero to about five percentof material selected from the group consisting of sodium, potassium, andammonium toluene sulfonates; sodium, potassium, and ammonium xylenesulfonates; and mixtures thereof.

3. The composition of claim 1 wherein the sulfate detergent is theammonium salt of the sulfate of the condensation product of one mole ofmiddle-cut coconut alcohol and an average of three moles of ethyleneoxide.

(References on following page) Cited by 1111: Examiner 2,877,185 3/59Krumrei et a1 252-137 2,999,068 9/61 Pilcher et a1 252-152 XR UNITEDSTATES PATENTS 2,060,568 11/36 Graenacher et a1. 2s2 -152 XR 30019459/61 Drew et 252 152 2,169,976 8/39 Guenther et a] 252-152 XR 5 FOREIGNPATENTS 2,310,074 2/43 Gotte 854 206,622 3/57 Australia.

2,607,740 8/52 Vitale et a1 252153 2,861,956 11/58 Fernandez 252-153JULIUS GREENWALD, Primary Examiner.

1. AN UNBUILT, HIGH-SUDSIN, LIGHT-DUTY LIQUID DETERGENT COMPOSTIONHAVING A PH OF FROM ABOUT 6.5 TO 9.0 AND HAVING SPECIAL UTILITY UNDERACID CONDITIONS SUCH AS MIGHT EXIST WHERE THE PH OF THE WASH WATER ISLESS THAN ABOUT 6.5 AND CONSISTING ESSENTIALLY OF (1) FROM ABOUT 20% TOABOUT 40% BY WEIGHT OF THE COMPOSITION OF A SULFATE DETERGENT HAVING THEFOLLOWING FORMULA